Australia and China struck their biggest trade deal ever yesterday as the world's two most valuable listed oil companies, ExxonMobil and PetroChina, agreed a $41-billion liquefied natural gas deal.

"It's a statement about the nature of our two economies and the fact that Australia is important to China, just like China is important to Australia," Australian Resources Minister Martin Ferguson said in Beijing.

The massive Gorgon LNG project operated by Chevron Corp, which owns a 50-percent stake, is located off Western Australia and has a proposed annual output of 15 million tons per annum (mtpa). Exxon and Royal Dutch Shell each own a 25-percent stake.